Create a commandline.txt file in your main GTA 5 folder to add parameters like -disableHyperthreading (for older CPUs) or -FrameQueueLimit 1 to reduce input lag.
Setting reflections to "High" instead of "Ultra" and disabling Reflection MSAA entirely can save up to 20 FPS . GTA 5 Best FPS Boost Guide 2023
This is the largest performance killer. Disabling MSAA entirely and using FXAA instead can provide a massive FPS boost (up to 30-40%) with minimal visual loss. Create a commandline
Moving from "Ultra" to "High" or "Normal" can reclaim roughly 10-20 FPS , particularly when driving through Blaine County. GTA 5 Best FPS Boost Guide 2023
Using DirectX 11 generally offers better stability and performance compared to older versions for modern hardware. System-Level Optimizations